Tone arm control device



Jan. 10, 1950 R. w. SIMON TONE ARM CONTROL DEVICE 2 Sheets-Sheet 1 FiledJune 4, 1947 IPEGINHLA, M41. MM, N /v' Inventor EN EN \N EN 9 5*;-Allorney5 e Jan. 10, R950 R. w. SIMON TONE ARM CONTROL DEVICE 2Sheets-Sheet 2 Filed June 4, 1947 Attorneys Patented Jan. 10, 1950UNITED STATES PATENT OFFICE Application June 4, 1947, Serial No. 752,361In Great Britain January 17, 1946 4 Claims.

This invention relates to gramophone pick-up devices and has for itsobject to provide an improved construction or arrangement designed tofacilitate the accurate placing of a needle in the required position ona record and to prevent damage to a record and a needle by the too rapidlowering of the pick-up arm into operative position.

According to the invention a device for controlling the position of agramophone pick -up arm comprises an arm or plate situated below thepick-up arm between the pick-up pedestal and the needle the said arm orplate being movable vertically about a horizontal spindle whereby thepick-up arm may rest upon it while being lowered into operative positionand the arm or plate thereafter moved lower and off contact with thepick-up arm until at the conclusion of a period of operation, the saidarm or plate is lifted to lift the pick-up arm and needle from therecord.

According to the preferred form of the invention a device forcontrolling the position of a gramophone pick-up arm comprises ahorizontal element carried by a pivoted component movable about ahorizontal spindle, the said horizontal element constituting a supportfor the pick-up arm while the needle is being positioned relatively to arecord and a hand operated eccentric device adapted to be operatedthereafter to enable said element to be given a slight lowering movementto bring the needle into engagement with the record.

Reference will now be made to the accompanying drawings which show aconstruction according to the invention and in which Fig. 1 is a plan ofthe device,

Fig. 2 is an end elevation,

Fig. 3 is a sectional elevation of the axial adjusting means,

Fig. 4 is a fragmentary plan showing the cam used in the device shown inFig. 3,

Fig. 5 is a sectional elevation of the device,

Fig. 6 is a cross sectional elevation,

Fig. '7 is a plan view showing the application of the invention to agramophone pick-up arm,

Fig. 8 is an elevation of Figure '7, and

Fig. 9 is-a plan view similar to Fig. 1 showing an alternative form ofthe invention.

In the construction illustrated a movable rod l is arranged, whenoperative, to extend in a radial direction across and above a record 2as shown in Figs. '7 and 8. The rod l acts as a support for the pick-uparm 3 which is free to move radially whilst resting upon the rod I. Therod l is carried in a sleeve or socket 4 mounted at the outer end of anarm 5 movable around a horizontal spindle 6 whose ends are carried in asupporting framework 1 which constitutes a fixed support for all thecomponent parts of the invention.

Mounted co-axially with the arm 5 is an operating lever 8 provided witha handle 9, this lever being formed integral with a disc l0 having aperipheral arcuate recess H in which engages a pin 23 rojectinglaterally from the arm 5-.

The lever B is mounted upon an eccentric sheave '12 disposed within asleeve 24 formed integral with the arm 5. Adjacent the end 26 of thelever B which surrounds the spindle 6 is a disc or Washer 21 which actsas a clutch member and is caused to bind more or less on the part '26 byo erating a knurled disc 28 which is screwthreaded on the spindle 6, thepurpose of this arrangement being to brake the lever 8 according to thetype and weight of the pick-up arm to which the invention is applied.

The lowermost position of the arm 5 an sleeve 4 is determined by anadjustable stop device consisting of a screw-threaded stem [3 whoseupper end is arranged to bear upon the the lower edge of the arm 5 andwhich is rotatably mounted in the supporting framework 1. A milled edgedwheel l4 surrounds and engages the stem l3, part of this wheelprojecting through a slot 25 in the framework 1 to facilitate manualadjustment. This adjustment is effected according to the thickness ofeach record but once effected does not need to be varied so long asrecords of a uniform type continue to be played.

In the operation of the devices above described, the arm 5 and rod 1 arelowered about the spindle 6, the rod occupying a position substantiallyas shown in Fig. 7 and the pick-up arm .3 is caused to rest upon the rodwhose position is such that the needle is held slightly above thesurface of the record. The fine adjustment necessary to bring the needleinto operative position is then effected by lowering the operatinghandle 8-9 which, owing to the pin 23 and recess I I, can move throughan are independently of the arm 5. This arcuate movement impartsrotational movement to the eccentric sheave 12 whose movement shifts thecentre about which the arm 5 pivots. During this movement the under edgeof the arm 5 slides on the stop pin I3 and being a tapered arm its outerend is thereby slightly lowered taking with it the rod l which is movedgently from beneath the pick-up arm 3 to allow the needle to comegradually into operative engagement with the record.

When the period of operation has been completed, upward movement appliedto the handle arm 89 will lift the rod I sufiiciently to engage beneaththe pick-up arm to lift it and remove the needle from engagement withthe record. Further movement applied to the handle arm 8-9 will causethe pin 23 to engage one end of the recess I I and lift the arm 5 androd I to an upper and completely inoperative position.

To enable fine mechanical control of the lateral movement of the pick-uparm to be effected and to facilitate the positioning of the needlerelative to the desired position of the sound track of the record anadditional device may be included in the structure. This device includesa rotatable nut or knob I5 mounted on a pin I 6 carried in a cylindricalextension H of the sleeve 4. Within the extension II, the pin I6 carriesa cam I8 and is rotatable in one direction to an extent determined by aspring I9 which returns the knob I5 sub sequently to a zero position.The cam I8 bears against a stud 2U projecting upwards from the rod Ithrough a slot 2| in the sleeve 4 and as the cam is rotated it bearsagainst the stud and causes axial movement of the rod I. provided withgraduations which in cooperation with a fixed pointer 22 enable thedesired degree of adjustment of the rod I to be effected. The shape ofthe cam is shown in Figure 4 and when zeroised by the action of thespring I9. The rod I is left in the adjusted position until depressionof the handle 9 brings it into contact with the end of rod I projectingbeyond the sleeve 4 and pushes the rod back to its initial position. Tofacilitate this operation the end of the rod I is chamfered. With thisarrangement it is possible to return to pre-selected position and forthe needle to be lowered into the required groove of the sound track forthe replaying of a given passage or part of a record. To facilitatethese operations the rod I may be graduated.

The means above described for axial adjustment of the red I do notconstitute an essential feature of the invention and in Figure 1 adevice is shown similar in all respects to that shown in Figs. 1-6 butwithout the axial adjustment device.

Where even greater accuracy in location of the groove in a record isrequired than is provided by the devices above described, a clamp may befitted to the turntable spigot having a pin thereon rotating on its ownaxis and which is arranged to engage the rod I when this rod is free ofthe pickup arm. When the pick-up arm is lifted free of the record, thepin is simultaneously dissengaged and thus provides an indication ofwhere disengagement was made and also provides a more accurate means oflocation for use in replacing the pick-up arm and needle in operativeposition.

I claim:

1. In a device for controlling the lowering.

movement of a phonograph tone arm into playing position and having theability substantially to lower the tone arm needle for playing andthereafter permit the needle to be gradually moved into actual playingrelationship with a record on the phonograph turntable, a framestructure, a horizontal spindle on said frame structure, an armrotatably mounted at one end upon said spindle, an elongated rod memberon the other end of said The knob I5 is arm, said rod being adapted toextend substantially radially above the phonograph turntable in positionto intersect the tone arm, when in its playing position, at a pointintermediate its needle end and its pivotal axis, relatively coarseadjustment means engageable with said arm and adjustable to vary theangular position of the arm with respect to said horizontal spindle andhence the proximity of said rod to the phonograph turntable, and aneccentric means operatively associated with said arm and adapted toeffect a precision lowering movement of said arm to remove the said rodgently from beneath the tone arm and thereby allow the needle to entergradually into playing contact with the record, said eccentric meanscomprising an operating lever, an eccentric sleeve on said spindle, saidarm being mounted upon said eccentric sleeve, and an operativeconnection between the sleeve and the said operating lever adapted inone direction of movement of the lever to impart movement to the saidsleeve to shift the center of said spindle to an extent and in suchmanner as gradually lowers the rod on said arm from beneath the tone armto allow the needle to engage a record.

12. The invention as defined in claim 1, said rod being mounted foraxial reciprocation upon said arm, adjustment means operativelyassociated with said rod to move the rod axially in one direction, saidadjustment means comprising a cam, mounting means rotatably supportingsaid cam adjacent said rod, a projection on said rod adapted forengagement with said cam to impart axial movement to said rod when thecam is adjusted in one direction of rotation, and resilient meansincorporated in said mounting means adapted to restore said cam to azero position.

3. The invention as defined in claim 1, said arm having a taperedsurface and said relatively coarse adjustment means comprising avertical adjustable spindle positioned to engage said tapered surface,said surface tapering off from the pivoted end of the arm to the endthereof on which the said rod is carried.

4. In a device as claimed in claim 1, a pin and slot connection betweensaid eccentric means and said arm adapted in one direction of movementof said eccentric means to efiect said gradual rod lowering movement andin the opposite direction of movement to raise the said rod intoposition to lift the tone arm needle from the record.

REGINALD WILLIAM SIMON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,441,511 Lagerquist Jan. 9, 19232,141,804 Thompson et al Dec. 27, 1938 FOREIGN PATENTS Number CountryDate 149,122 Great Britain Aug. 12, 1920 188,130 Great Britain Nov. 9,1922 524,789 Great Britain Aug. 14, 1940 522,704 Germany Apr. 16, 1931

